什么是收率曲线控制，以及对之分析。
Yield curve control (YCC) involves targeting a longer-term interest rate by a central bank, then buying or selling as many bonds as necessary to hit that rate target. This approach is dramatically different from the Federal Reserve's typical way of managing U.S. economic growth and inflation, which is by setting a key short-term interest rate, the federal funds rate.
收益率曲线控制是指央行设定长期收益率目标，然后通过购买或者卖出需要的债券来达到收益率目标。这种路径于美联储管理美国经济增长与通胀的典型方式极不相同。经济管理是通过设定短期关键利率，即联邦基础利率。
Advocates of yield curve control, also called YCC, argue that, as short-term interest rates approach zero, keeping longer-term rates down may become an increasingly more effective policy alternative for stimulating the economy. Also, this approach could help prevent a recession or lessen the impact of a downturn. Richard Clarida and Lael Brainard, current members of the Board of Governors at the Fed, as well as former Fed chairs Ben Bernanke and Janet Yellen have said that the Fed should consider using yield curve control.Jerome Powell, the current Fed chairman, also has said that he is potentially open to this policy option.
YCC的主张者认为，随着短期利率接近于零，不断的降低长期利率相较于刺激经济是一个更为有效的刺激方式。并且，这种方式能够防止经济衰退，或者让下滑更小。Richard Clarida 和Lael Brainard ，现任Fed的决策委员会成员，以及前Fed主席 Ben Bernanke，Janet Yellen 都说过Fed应该考虑使用YCC工具。现任Fed主席Jerome Powell，也说过他对此项政策持开放态度。
Key Takeaways 要点
Yield Curve Control (YCC) by the Fed would target specific long-term rates levels.
It sharply differs from quantitative easing (QE) in its approach.
YCC may be needed for economic stimulus as short-term rates near zero.
Former Fed chairs Bernanke and Yellen support the use of YCC.4
How YCC and QE Differ
Through quantitative easing (QE) designed to combat the 2008 financial crisis and Great Recession, the Fed injected liquidity into the financial system through massive purchases of bonds on the open market. This bid up the prices of bonds, thus reducing longer-term interest rates and borrowing costs.
QE旨在应对2008年金融危机和大萧条，Fed通过大量在公开市场大量购买债券来向金融系统注入流动性。这种方式抬高了债券价格，因此降低了长期利率和借贷成本。
However, during the financial crisis, the Fed was not seeking to set a specific long-term interest rate. By contrast, under yield curve control, the Fed would set a specific long-term interest rate target and buy as many bonds as necessary to achieve it. YCC would set a specific price for the bonds in terms of their yield.
但在整个金融危机期间，Federal并没有寻求设定具体的长期收益率。相比之下，YCC方式，Fed将设定具体的收益率目标，并购买尽可能多的债券来实现他。 YCC按照具体的收益来设定具体的债券价格。
Examples of YCC Programs
During World War II, massive borrowing by the U.S. federal government was necessary to fund the war effort. However, this threatened to send interest rates soaring, making such debt increasingly more burdensome to service. In response, from 1942 to roughly 1947, the Fed successfully kept the government's borrowing costs down by purchasing any government bond that yielded more than certain targeted rates. Notably, the government was able to reach its goals with relatively modest bond purchases.
二次世界大战期间，联邦政府需要大量的举债来应对战争耗费。但是，大量的借债会造成收益率飙升，使得此类债务负担更重。作为回应，从1942到大约1947，Fed通过够买超过特定利率的国债以降低政府的债务成本。值得注意的是，政府通过适度的债券购买来达到目标。
这是不是一种事实上的债务货币化呢？
More recently, the Bank of Japan (BoJ) shifted in late 2016 from a policy of QE to one of YCC, in which it sought to peg the yield on 10-year Japanese Government Bonds (JGBs) at 0%, in a effort to stimulate Japan's economy. Whenever the market yields on JGBs rise above the target range, the BoJ purchases bonds to push the yield back down.So far, the BoJ has been purchasing bonds at a slower pace than under QE.2
日本央行-BoJ在2016年末从QE政策转换为YCC政策: 试图将10Y 日本政府债券盯在0%，希望如此能刺激日本经济。当JGBs市场利率超过目标利率，BoJ会购买债券来降低收益率。到目前为止，日本央行购买债券的步伐要比量化宽松的节奏更慢。
Advantages and Disadvantages of YCC vs. QE 利与弊
Pointing to the recent BoJ experience, advocates of YCC believe that the Fed also can achieve lower interest rates with a much smaller balance sheet than it built under QE.Not everyone is confident that YCC will work. An opinion piece in Bloomberg has described YCC as a 'bond trader's nightmare,' citing lengthy periods in which JGB trading has ground to a halt. Moreover, YCC could spur companies to increase their already heavy debt loads, while punishing pension funds and other savers.
根据BoJ经验，YCC的倡导者认为Fed也能通过比QE更小规模的资产负债表来实现更低的利率。当并不是所有人都对YCC运作有信心。彭博有篇文章认为YCC是债券交易者的噩梦： JGB交易长期停滞。而且，YCC将刺激公司增加本已负担沉重的债务，同时惩罚了养老基金和其他储蓄者。